Steam-turbine construction



Oct. 9, 1928.

1,687,103 A. MEYER ETAL v STEAM TURBINE CONSTRUCTION Filed Feb. 19, 1926 Patented Oct. 9, 1928.

SWITZERLAND, ASSIGNORS TO A. G. BROWN BOVERI & CIE., OF BADEN, SWITZER- LAND, A J OINT-STOCK COMPANY OF SWITZERLAND.

STEAM-TURBINE CONSTRUCTION.'

Application filed February 19, 1926, Serial No. 89,451, and in Germany April 23, 1925 This invention has to do withsteam turbine construction, particularly with the arrangement of the. cylinder or diaphragm, blade mountings for disposal of water condensed in b the turbine.

V The general object of the invention. is the provision of a construction whereby-water of condensation may be discharged or with drawn from the cylinder blading, and which may be built economically and without weakening the cylinder or adding to its weight or bulk.

Other objects will be pointed out or indicated hereinafter, or obvious to one skilled of guide blades to a stage of rotor blades in a steam turbine.

Fig. 2 is a detail in the nature of a part longitudinal section through aportionof an.

impulse turbine showing the arrangementat the junction of the diaphragm'or the blade mounting and casing or cylinder.

Fig. 3 is a similar section through the mountings of adjacent guide blade stages, showing a modification.

Fig. 4 is a cross sectional view through the,

mounting of a guide blade.

through adjacent guide blade mountings, showing another modification.

Fig. 6 is a similar view of a modification of the form shown in Fig. 5.

Fig. 7 is a longitudinal sectional detail on approximately line 77 of Fig. 5.

Fig. 8 is a transverse sectional elevational detail through the lower portion of the cylinder, and c Fig. 9 is a longitudinal section elevational view showing the arrangement of discharge channels.

Considerations of efiicient operation of steam turbinesmake desirable the use of the Fig. 5 isan elevational sectional detail I blades.

the velocity of water leavin the same.

highest feasible steam pressures and vacua forthe purpose of giving the greatest possible heat drop. Increase in pressure and vacuum I j 1,687,103 UNITED STATES [PATENT o FlcE.

ADOLF MEYER, or KUSNAGHT, NEAR ZURICH, AND KARL Easy, on ENNETBADEN,

is attended, however, with the undesirable effect of increasing condensation of steam in the low pressure stagesof the turbine, resulting in loss of energy andgerosion of the blading.

Itfhas been proposed to provide annular channels cast in the cylinder between the stages of guide bladesfor the purpose of conducting off the condensate. Such constructlons, however, considerably. increase cutting,- weaken the same unless the casting is reinforced by additional thickness. This, however, means further increased cost attended with thedanger of there being pipes in the casting owing to the extensive thickness of metal. By the present invention we obviate these difficulties and provide an effective construction whichmakes adequate provision for the disposal of the condensate,

lends itself readily to manufacturing operaassembled, and occasions no w'eakeningor increase 1n bulk ofthe casing or of the blading or blade. mountlngn. This we accomplish by forming the blade-mountingof the casing or cylinder in such a fashion asto provide annular spaces for, conductingofi' 'the condensate between the stages of blade mountings, with suitable communicating passages extending through the blade mountings for permitting fiow of the condensate longitudinall of the casing to discharge channels.

. The nature of the invention will be under stood more in detail from the illustrative forms shown. In the first place, to demonstrate the detrimental effect of accumulations of condensate in the blading, reference is -made to Fig. 1,'where a designates a stage of the cost of the casing and when formed by tions, involves, no additional parts, is easily guide blades and 7 an adjacent stage of rotor The component 0 designates velocity of steam leaving the guide blading, and b Subtractingthe peripheral velocity u gives resultant e with which the steam enters the moving blades in the most favorable direction. The Water, however, leaves in the direction d striking the backs of the moving blades at g, resulting in a force opposing their movement and in destructive erosion.

In Fig; 2 is shown a construction fora with the bore surface of the cylinder.

cylinder in'whi'ch 'diaphragms are used be tween the rotor stages, such, for example, as in a turbine of the impulse type. In this fig .ure the reference numeral 10 designates a por tion of the casing or cylinder in which is mounted the portion 11 of the blade mount.-

ing, which, with the disc portion 12, supports nally of the casing, whereby the water may be drained from the channels entirely outside the periphery of the guide and rotor blades. These passages are provided at such intervals as may beappropriate and in most instances will be arranged at closer intervals in the bottom port-ion of the cylinder than in the more elevated portions. In Fig. 3 is shown another construction wherein the blade mountings are in the nature of extension or root portions formed on the blade, together with separate spacing members inserted between the blade roots and operating to anchor them in place in annular slots in the casing, the eas ing here being designated 10, the blades 14: and the blade mountings 11. In this form, as in the form illustrated in Fig. 2, the passages 16 are shaped as tunnels or bores. Fig. 1 shows the cross sectional view, illustrating one shape of the spacing members 11 which form part of the blade mounting. In Figs. 7 and 5 is shown another form 'of the blade mounting, in which the passages 16 are formed as grooves extending transversely in the spacing pieces with their bottoms flush In Fig. 6 is shown yet another arrangement in which the spacing members 11" of the blade mounting are reduced in height throughout their full area so as'to be flush with the bore of the cylinder. It will be understood that with any of these various embodiments the I spacing members are formed to afford the passages which are arranged at appropriate intervals in the stage of guide blading. In Fig. 8 a number of them are shown interposed between adjacent blades at the lower portion of the casing. For the purpose of removing the condensate from the casing, the latter may be provided with longitudinal conduits 17 communicating wit-h channels '15 by Way of the passages 18,=the casing being increased in thickness as at 19, if desired, to accommodate said. conduits. This may be done without increasing the weight of the casing. Of course, various other arrangements of discharge passages maybe provided.

What we claim is:

1. In steam turbine construction, aIst-ator 1 casing, and fixed blademountings extending lnwardly from the casing bore surface to afford intervening channels extending'in the circumferential direction of the casing,*said mountings being provided with passages arranged for drainage of liquid from one of said channels to another.

2. The construction as in claim 1, wherein the outer walls of the passages are flush with the casing bore surface.

3. The construction as in claim 1, wherein the blade mountings include'spacing pieces between blades, said passages being provided through the spacing pieces. 1

4c. The construction as in claim 1, wherein the blade mountings include spacing pieces between blades and the passages extend the full width of the spacing pieces;

5. The construction as in claim 1, wherein the casing wall affords longitudinal conduits channels; r I

6. The construction as in claim 1, wherein the blade mountings are of annular form.

for conducting condensate away from the.

7. The construction as in claim 1, wherein theouter walls of the-channels are the normal bore surface of the casing. I 8. The construction as specified in-cla m 1,

wherein outlets are provided for conducting 

